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From: Ralf Baechle <ralf@linux-mips.org>
To: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: John Crispin <blogic@openwrt.org>,
	linux-mips@linux-mips.org, Felix Fietkau <nbd@openwrt.org>
Subject: Re: [PATCH RESEND 16/17] MIPS: make oprofile use cp0_perfcount_irq if it is set
Date: Thu, 12 Jan 2012 18:02:51 +0100	[thread overview]
Message-ID: <20120112170251.GA21781@linux-mips.org> (raw)
In-Reply-To: <4F0EFE6E.3080503@mvista.com>

On Thu, Jan 12, 2012 at 06:38:22PM +0300, Sergei Shtylyov wrote:

> >@@ -374,6 +379,10 @@ static int __init mipsxx_init(void)
> >  	save_perf_irq = perf_irq;
> >  	perf_irq = mipsxx_perfcount_handler;
> >
> >+	if (cp0_perfcount_irq>= 0)
> 
>    BTW, I just noticed. IRQ0 is not a valid IRQ in Linux,
> request_irq() should fail when passed 0, so this and following check
> should be '> 0'.

In a normal configuration that is in a discrete processor or in a MIPS
core where the performance IRQ is just routed back into the core the
lowest sensible value for cp0_perfcount_irq is 2, so there is no
immediate problem there.

IRQ 0 is ok for static use; dynamic use is problematic.  This case is
even more problematic because the interrupt might be shared with the
timer and the timer interrupt is allocated statically (see cevt-r4k.c)
but the performance counter interrupt later allocated dynamically with
IRQF_SHARED.

  Ralf

  parent reply	other threads:[~2012-01-12 17:02 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-11 20:44 [PATCH RESEND 01/17] MIPS: lantiq: reorganize xway code John Crispin
2012-01-11 20:44 ` [PATCH RESEND 02/17] MIPS: lantiq: change ltq_request_gpio() call signature John Crispin
2012-01-17 14:19   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 03/17] MIPS: lantiq: make irq.c support the FALC-ON John Crispin
2012-01-17 14:19   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 04/17] MIPS: lantiq: add basic support for FALC-ON John Crispin
2012-01-11 20:44 ` [PATCH RESEND 05/17] MIPS: lantiq: add support for FALC-ON GPIOs John Crispin
2012-01-11 20:44 ` [PATCH RESEND 06/17] MIPS: lantiq: add support for the EASY98000 evaluation board John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 07/17] MIPS: lantiq: fix early printk John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 08/17] MIPS: lantiq: fix cmdline parsing John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 09/17] MIPS: lantiq: fix STP gpio groups John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 10/17] MIPS: lantiq: fix pull gpio up resistors usage John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 11/17] MIPS: lantiq: add default configs John Crispin
2012-01-17 14:20   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 12/17] MAINTAINERS: add entry for Lantiq related files John Crispin
2012-01-11 20:44 ` [PATCH RESEND 13/17] NET: MIPS: lantiq: make etop ethernet work on ase/ar9 John Crispin
2012-01-17 14:21   ` Ralf Baechle
2012-01-11 20:44 ` [PATCH RESEND 14/17] NET: MIPS: lantiq: non existing phy was not handled gracefully John Crispin
2012-01-11 20:44 ` [PATCH RESEND 15/17] NET: MIPS: lantiq: return value of request_irq " John Crispin
2012-01-12 11:33   ` Sergei Shtylyov
2012-01-11 20:44 ` [PATCH RESEND 16/17] MIPS: make oprofile use cp0_perfcount_irq if it is set John Crispin
2012-01-12 11:37   ` Sergei Shtylyov
2012-01-12 15:38   ` Sergei Shtylyov
2012-01-12 14:49     ` Guenter Roeck
2012-01-12 17:02     ` Ralf Baechle [this message]
2012-01-11 20:44 ` [PATCH RESEND 17/17] MIPS: lantiq: enable oprofile support on lantiq targets John Crispin
2012-01-17 14:22   ` Ralf Baechle
2012-01-13 12:38 ` [PATCH RESEND 01/17] MIPS: lantiq: reorganize xway code Ralf Baechle

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